The construction and functionality of anchors is well known in the relevant art. Basically, anchors are intended to be embedded into a piece of material, and to hold and to firmly retain a fastener therein once it has been embedded or otherwise inserted into the piece. Anchors are particularly desirable for use with materials which themselves lack the structural integrity sufficient to firmly hold and retain fasteners directly. Gypsum board, commonly known as drywall, is one example of such a material. With the use of anchors, objects which otherwise could not be mounted on drywall solely by fasteners can be mounted on the drywall. An example of a self-drilling dry wall anchor is disclosed in the U.S. Pat. No. 4,601,625 to Ernst et al.
To insure that the anchors will remain firmly within the drywall, or other material, the anchors are often self-drilling. The anchors have a drilling section disposed on its entering end which is capable of removing portions of the drywall upon application of an axial torque to the head of the anchor. In this way, it is assured that the bore formed through the drywall will not be too big. By self-drilling its own bore, the anchor assures that the bore will be of proper size, and will firmly retain the anchor therein, thereby preventing anchor pull out.
Self-drilling does, however, present difficulties on occasion. As the anchor drills its own bore through the drywall, particulate is formed from the drilled portions of the drywall. This particulate can fill the bore as it is formed and become compressed by further drilling of the anchor, thereby complicating the self-drilling process. Additionally, once the anchor has reached the opposite edge of the drywall, no means are provided for facilitating removal of the particulate from the bore.
The presence of the particulate in the bore can make the self-drilling process more difficult, prohibiting good tapping of the anchor into the drywall. The particulate can resist the torque on the anchor. Also, the particulate may rotate along with the anchor, possibly enlarging the size of the bore. If the bore is enlarged, the anchor can pull out of the bore upon the application of an appropriate force, such as that usually attendant with the mounting of objects, such as picture frames and the like, on the drywall. Additionally, the presence of the particulate can maximize the effects of torque on the anchor, thereby causing it to break as a fastener is inserted therein. The anchor of the present invention is intended to alleviate these, among other, drawbacks of anchor constructions of the prior art.